<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <style>
        ul{
            list-style-type: none;
        }
    </style>
    <title>测试ul</title>
</head>
<body>
    <ul>
        <li>aa</li>
        <li>bb</li>
        <li>cc</li>
        <li>dd</li>
    </ul>
</body>
</html>